Mechanics | Relativity Answers

The footballer kicked the ball and it was caught by the opposing goalkeeper, 4 metres above the ground. The ball was traveling at 10 m/s^2.Calculate the kinetic energy of the ball just before it was caught.

a cube made of an unknown material has a dimension of 6cm on all edges . if the upper face is displaced laterally by 0.1 mm by a force of 2 x 10 ^6 dynes acting parallel to the surface , calculate the shear modulus of the material

 John, in going to his Physics class, walks 30m, 450 N of E, then 40 m, 600 W of S and finally 50 m, straight south. Use the polygon method to determine the resultant vector 𝑅⃑ and check your result using the component method.

The displacement of an object executing simple harmonic oscillations is given by:

x = 0.02 sin 2π ( t + 0.01 ) m

Determine (a) amplitude of the oscillatory motion, (b) time period of oscillation , (c) maximum velocity, (d) maximum acceleration, and (e) initial displacement of the object.

A KTM commuter train travels between two stations, A and B. The train starts from rest from station A and accelerates at a constant rate for 0.5 km until it reaches a speed of 30 m/s. It then travels at this constant speed for T s before decelerating at a constant rate of 1.5 m/s² and coming to rest at station B. Figure 1 shows the velocity-time graph of the train’s journey between the two stations. Determine the value of T if the distance between the two stations 6 km. Calculate also the total time taken for the whole journey.

A car is speeding up and has an instantaneous velocity of 1.0 m/s in the +x-direction when a stopwatch reads 10.0 s. It has a constant acceleration of 2.0 m/s² in the x-direction. (a) What change in speed occurs between t = 10.0 s and t = 12.0 s? (b) What is the speed when the stopwatch reads 12.0 s?

A square field measuring 100.0 m by 100.0 m has an area of 1.00 hectare. An acre has an area

of 43,600 ft2

. If a country lot has an area of 12.0 acres, what is the area in hectares?

An object weighing 58,800 N rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab?

A flower pot is accidentally dropped from a building window 400m from the ground. Assuming it starts from rest, a How long will it take the pot to reach the ground?

A body of mass 12.0kg is placed on an orange tree 20.0m above the ground.

1. Calculate it's potential energy with respect to the ground.

2. If the body is released from thos height,what will be it's kinetic energy just before it hits the ground.