Mechanics | Relativity Answers

A ball is thrown vertically upwards from the top of the tower with a speed of 40m/s returns back to ground level in 10s.The height of the tower is

A pi meson is moving at a speed of 0.85c relative to a flat surface. The flat surface has a length of 3.2m when at rest on Earth. Calculate the length of the flat surface in the reference frame of the pi-meson.

1. an automobile travels 9 miles due south, then 20 miles in a direction 40 degrees south of east, determine the resultant displacement.
2.find the sum or resultant of the following displacements: A, 10 ft northwest, B, 20 ft 30 degrees north of east; C, 35 ft due south.
3.which of the vector r = xi+yj+zk makes with the positive directions of the coordinate axes.
4.An airplane pilot sets a course due north and his speed is 150km/hr. There is a wind 40km/hr from the east. What is the actual velocity of the airplane?
5. A river flows at a steady speed of 3m/s. A man wishes to cross in a motorboat which travels at 5km/hr so as to reach a point directly across the river. In what direction should he steer?
6. if r1 = 2i-j+k, r2 = i+3j-2k, r3 = -2i+j-3k and r4 = 3i+2j+5k, find the scalars a, b, c such that r4=ar1+br2+cr3

Wall-E does 750J of work pushing a block of rubbish 15m. Calculate the force he is pushing with.

A projectile is launched from ground level with an initial speed of 47.5 m/s at an angle of 33.3° above the horizontal. It strikes a target in the air 2.82 seconds later. What are the horizontal and vertical distances from where the projectile was launched to where it hits the target?

a 5 meter long wire is fixed to the ceiling. a weight of 10kg is hung at the lower end and is 1 meter above the floor . the wire was elongated by 1mm . the energy stored in the wire due to stretching is

I have put a 100 gram weight ball in a plastic bottle and weight of this bottle is 20 gram .Now I shake this bottle in horizontal direction towards 5 centimeter back and forth with the applying force of 1 newton .So what will be the kinetic energy of this ball?

which of the following is not an effect of negative feedback?
a) reducing the effect of noise
b) reduction in voltage gain
c) increase in system bandwidth
d) increase in harmonic distortion

A 1400 kg car is traveling at 24 m/s when the driver takes his foot off of the gas. The car eventually rolls to a stop after 225 m. Find the force of friction acting on the car.

Why must you use reference point (h0) on the spring for each subsequent height measurement?