Mechanics | Relativity Answers

A projectile fired at O follows a parabolic trajectory, given in parametric form by:

x = 86t and y = 96t – 4.9t2

where x and y are measured in meters and t in seconds. Determine:

(a) ax and ay at any time t

(b) vx and vy at any time t

(c) initial velocity, vo (velocity at pt O)

(d) velocity when t = 5s (hint: get first vx and vy at t = 5s)

(e) maximum height h

(f) horizontal distance L

How do I Calculate the mass of a ball that is 5m above the ground with a GPE of 10J

Mark is driving to school when he hits a deer. Immediately after the collision, with the deer on the hood of his car, Mark looks at the speedometer and sees that he has a velocity of 13.0 m/s. The deer has a mass of 70.0 kg and Mark’s car has a mass of 1150 kg. The deer was at rest before the collision. a) How fast was Mark going when he hit the deer? b) Was this collision elastic or inelastic? SHOW ALL OF YOUR WORK!

Thank-you!

A golf ball with mass 45.90 g and diameter 42.60 mm is struck such that it moves with a speed of 54.15 m/s while rotating. The golf ball has a kinetic energy of 67.67 J. What is the rotational frequency of the golf ball (in rpm)?

A truck with a 1000kg load sitting on its flat deck is driving round a circle of radius 100m on a flat, horizontal road at a steady speed of 10ms-1 (36kmhr-1). The load is not secured, but is not sliding on the flat deck of the truck. Which ONE of the following statements is FALSE?

(a) The magnitude of the acceleration of the load is 1ms-2
(b) The upward normal force on the load is 10000N
(c) The total vertical force on the load is zero
(d)The total horizontal force on the load is zero
(e) The magnitude of the frictional force on the load is approximately 1000N

A strong spring is used to launch a 2kg mass horizontally. The spring has a spring constant of k=8000Nm-1 and you wish the mass to have a velocity of 32ms-1 as it leaves the end of the spring. What initial compression of the spring, from its equilibrium position, is required to produce this velocity (in m)?

(a) 0.1
(b) 0.3
(c) 0.5
(d) 0.7
(e) 0.9

A uniform 10 m long, 50 kg pole is lying on the ground. You get your little brother to lift at one end with an upward force of 100N. How far from the other end will you need to lift so the pole stays horizontal (in m)? [Hint: Using your little brother as the fulcrum, what upward force in N, will you need to apply?]

(a) 2.5
(b) 3.8
(c) 5.0
(d) 6.7
(e) 7.5

A jet of water of 10 mm diameter impinges normally on a smooth flat
plate of 50 N in weight as depicted below. The water is deflected and
flows out along the plate and the plate remains stationary. Assume the
friction loss and head difference are negligible, determine the flow rate.

A block slides down a frictionless plane having an inclination of θ = 15.2°. The block starts from rest at the top, and the length of the incline is 2.80 Determine the acceleration given this system.

A monkey climbed to a vertical high, using a vertical rope in 30 seconds .It used a constant velocity for that motion .Then it climbed to that same vertical high,using a spiral path( which was 75 in length) .Throughout that spiral path,there was another constant velocity .Throughout the entire in both cases , it used a same power .

how much was the velocity in that spiral path?

answer is 2.5 per minute,

power gained by itself is constant and same in both times,high also same,but velocities are different,then how is energy constant ?