Mechanics | Relativity Answers

A 24 g block of ice is cooled to -88°C. It is added to 538 g of water in an 91 g copper calorimeter at a temperature of 29°C. Find the final temperature. The specific heat of copper is 387 J/kg • °C. The latent heat of fusion of water is 3.33 x 10^5 J/kg and its specific heat is 4186 J/kg • °C.
Answer in units of °C.

Block 1, of mass m1 = 5.90 kg , moves along a frictionless air track with speed v1 = 17.0 m/s . It collides with block 2, of mass m2 = 59.0 kg , which was initially at rest. The blocks stick together after the collision.

A
Find the magnitude pi of the total initial momentum of the two-block system.

B
Find vf, the magnitude of the final velocity of the two-block system.

C
What is the change ΔK=Kfinal−Kinitial in the two-block system's kinetic energy due to the collision?

The sun is approximately 25,000 light years away from the centre of milky way and moves around it,in an approximately circularly path,in roughly 170 million years.given the sunlight takes approximately 8 mins to reach the Earth ,what is the ratio of masses of galaxy and sun?

A wheel 2.0 m in diameter lies in the vertical plane and rotates about its central axis
2
Take g  10ms
.
with a constant angular acceleration of 4.0rads
t  0 and the radius vector of a point A on the wheel makes an angle of 60o with the
. The wheel starts from rest at horizontal at this instant. Calculate the angular speed of the wheel, the angular

1) An object travels with a speed of 4 m/s toward a frictionless incline.
a) How high up the incline will the object travel?
b) If the angle of the incline is doubled (so the incline is steeper), how will this affect how high up the incline the object travels?
2) At the top of a 3 m high frictionless ramp, an object is moving at 2 m/s.
a) How fast will it be traveling when it reaches the bottom of the ramp?
b) How fast will the object be traveling when it is halfway down the ramp (i.e., at a height of 1.5 m above the ground)?

Calculating the momentum of a 2.0g feather moving at 3m/s?

Then the kinetic energy of the feather from problem 1 in joules

A 2.30 N object vibrates at the end of a vertical spring. If the frequency of the vibration is 1.00 Hz, what is the spring constant?

This one is giving me trouble.

A motor boat is heading due north and crosses a wide river with a speed of 4m/s relative to the water. the water in the river has a uniform speed of 3m/s due east relative to the earth . determine the direction of the motion of the motor boat relative to the earth

a child of mass 30kg skates down from the top of a ramp having a constant slope of 15degree. the childs speed increases from 1.5m/s to 3m/s as she reaches the bottom of the ramp. a force of kinetic friction of magnitude 50N opposes her motion. draw the appropriate force diagram and determine the length of the ramp. take g=10m/s²

Mike is cutting the grass using a human-powered lawn mower. He pushes the mower with a force of 45 N directed at an angle of 41 N below the horizontal direction. Calculate the work that Mike does on the mower in pushing it 9.1 m across the hard.