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1. A force of 3.6 N acts towards the East on an object with mass m = 2.0 kg, while simultaneously a force of 2.2 N acts towards the South on the same object. What is its acceleration? ( correct number of sig fig).

a) Magnitude of the acceleration a = _____ m.s^-2 at

Using the information from question #703a above:
b) an angle of _____ ∘ South of East.

2. It is said that a mouse (a very small mammal) can fall 10 m and walk away, unharmed. If a moose (a very large mammal) fell 10 m it would probably not survive. Why is this? Select the best answer. (We don't say this often, but don't answer this one experimentally.)

a) the air resistance acting on the mouse is greater
b) the mouse decelerates over a shorter distance
c) the mouse's terminal speed is greater
d) the mouse hits the ground at a lower speed
e) the mouse is stronger than the moose
1. When visiting the Italian town of Pisa, young physics student Isaac Galilei drops an apple with a weight of 2.0 N from the city's famous leaning tower. The apple falls 56m to the ground. First question: Ignoring air resistance and other subtle effects, how long does it take the apple to fall to the ground? The apple takes _____ s to fall to the ground (correct sig fig).

2. The story so far: Visiting the Italian town of Pisa, young physics student Isaac Galilei drops an apple with a weight of 2.0 N from the city's famous leaning tower. The apple falls 56 m to the ground. We've just seen that the apple takes 3.4 s to reach the ground. o… while the apple falls downwards, how far does the Earth fall up towards the apple? (Ignore all effects except the Earth-apple interaction.) Should you need them, here are some data: The mass of the Earth is 5.97 x 10^24 . (You don't need to know that its radius is 6371 km and that G = 6.67384 × 10^ -11 m^3 kg^-1s^-2.
1. A bicycle is travelling at constant velocity on a horizontal road. Which of the following statements are true? (You may choose more than one.)
a) The total force on the bicycle is parallel to the motion.
b) The total force on the bicycle is anti parallel to the motion.
c) No forces are acting on the bicycle.
d) Various forces are acting on the bicycle, and their sum is zero.
e) Air resistance forces are approximately parallel to the velocity.
f) Air resistance forces are approximately anti parallel to the velocity.
g) Overall, friction between the tires and the road is pushing the bicycle forwards.

2. A slack rope walker balances on a rope tied between two trees. For a short time, he is not moving. His mass is 72 kg. The rope makes an angle theta = 22 degrees with the horizontal on either side. What is the magnitude of the tension in the rope?
Week 4

1. This artist's conception imagines a 'wheel-shaped' space station. The idea is that the 'wheel' would turn on its axis at a rate such that the acceleration in the rim of the wheel would be 9.8 m/s^2. (This would make inhabitants feel as though they had their normal weight.) Suppose that the radius of the wheel is 1.0 x 10^2 m. What is the required period of rotation of the space station about its axis? (Follow the significant number for the final answer).
A portable animal cage that weighs 9,856 N rests on the floor. How much work (in J) is required to lift it 7.9 m vertically, at constant speed?
P=12N, Q=5N, theta=120 degrees
Find the resultant force and alpha

A child is sitting in a chair connected to a rope that passes over a friction less pulley .the child pulls on the loose end of the rope with a force of 250 N .the child's weight is 320 N and the chair weights 160 N .the child is accelerating .find the force that the seat of the chair exerts on the child?


1. Suppose that an astronaut, wearing a space suit on Earth, can kick a ball a distance of 25 m. Using the datum gravitational acceleration is g = 1.6 m/s^2, estimate how far he could kick the ball on the moon, using the same action and kicking at the same angle. (Remember significant figures and neglect air resistance. Assume that the launch and landing heights are the same. Do not use exponent notation.)


2. This artist's conception imagines a 'wheel-shaped' space station. The idea is that the 'wheel' would turn on its axis at a rate such that the acceleration in the rim of the wheel would be 9.8 m/s^2. (This would make inhabitants feel as though they had their normal weight.) Suppose that the radius of the wheel is 1.0x10^2 m. What is the required period of rotation of the space station about its axis?
Period of rotation = _____ s. (Enter the number without using exponent notation.)
1. You've made it to the top deck on the diving tower, 10 m above both the ground level deck and the water, and 3 m wide. Your friend has dared you to run and jump horizontally, so as to go as far forwards as you can before hitting the water. But you see that the far side of the pool is only 10 m from the edge of your platform.

a) Treating yourself as a projectile (something only recommended in theory) travelling horizontally as you leave the platform. How fast would you have to run in order to travel 10 metres horizontally before hitting the water? Give your answer to only one significant figure.

b) What horizontal acceleration do you need to achieve the speed calculated in (a)?

3. Here, I am swinging a ball around in a horizontal circle with a radius of 0.60.
a) What is its vertical component of acceleration?
b) At what constant speed must it travel so that the horizontal component of its acceleration is 2.1 m/ s^2.
1. (Part a) A juggler throws balls almost vertically upwards, with time delta t = 0.23 s between each throw. (Yes, pretty amazing.) The balls are all thrown to the same height, and in repeated succession (e.g. 1, 2, 3, 1, 2, 3 etc.). Let's simplify: neglect air resistance, neglect the time between catching and throwing a ball and assume that balls are thrown and caught at the same height. Calculate the minimum height he must throw the balls if he is to juggle

3 balls? _____ m

(Part b) Using the information from question (part a) above: Calculate the minimum height he must throw the balls if he is to juggle

5 balls? _____ m