Mechanics | Relativity

During lift off a rocket ship accelerates from rest to

about 28000 km/h and reaches an altitude of 300 km.

What is the apparent weight of a 75 kg astronaut during

this time (assume constant acceleration)? Explain why

does an astronaut feel weightless once in orbit?

about 28000 km/h and reaches an altitude of 300 km.

What is the apparent weight of a 75 kg astronaut during

this time (assume constant acceleration)? Explain why

does an astronaut feel weightless once in orbit?

Mechanics | Relativity

A pulley system has the following characteristics;

box one has a mass of 2.0×10 to the power of 3 kg, box 2 is at a 90° angle below box one attached by a rope and has a mass of 4.4×10 to the power of 2 kg, the man on top of box 2 has a mass of 6.0×10 to the power of 1 kg. if all surfaces are frictionless, what is the apparent weight of the man?

box one has a mass of 2.0×10 to the power of 3 kg, box 2 is at a 90° angle below box one attached by a rope and has a mass of 4.4×10 to the power of 2 kg, the man on top of box 2 has a mass of 6.0×10 to the power of 1 kg. if all surfaces are frictionless, what is the apparent weight of the man?

Mechanics | Relativity

A ball is thrown horizontally at a velocity of 10.0 m/s from the top of a 90.0 m building. Calculate the distance from the base of the building that the ball is safely caught on the ground.

Mechanics | Relativity

A contraption shows the following m1 = 2.0 x 103 kg, m2 = 4.4 x 102 kg, the man on top of m2 has a mass m = 6.0 x 101 kg, and all surfaces are frictionless. What is the apparent weight of the man?

Mechanics | Relativity

Two particles P and Q move towards each other along a straight line MN, 51 meters long. P starts from M with velocity 5ms^{-1} and constant acceleration of 1ms^{-2}. Q starts from N at the same time with velocity 6ms^{-1} and at a constant acceleration of 3ms^{-2}.

Find the time when the :

A) particles are 30m apart

B)Particles meet

C) velocity of P is ¾ of the velocity of Q

Mechanics | Relativity

A tennis ball of mass 56 gm is projected vertically upward with average velocity 48.1 m/s. Calculate the kinetic energy after 5 seconds

Mechanics | Relativity

A support supplies a force 5 kN to a wall as shown below. What is the x component of the moment (in kN-m) produced by this force about an axis in the direction of i+j+k(from the origin)?

Mechanics | Relativity

• A 50.0 kg circus acrobat drops from a height of 2.0 m straight down onto a springboard with a force constant of 8.00 × 103 N/m. By what maximum distance does she compress the spring?

• Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 20.0 m above water with an initial speed of 15.0 m/s strikes the water with a speed of 24.8 m/s independent of the direction thrown.

Mechanics | Relativity

A rod of length Lo = 1m, moves with speed v equivalent to 77% of the speed of light c along the y-axis direction. At rest, the rod makes an angle of 35 ° with respect to the x- axis.

a) Determine the length of the rod as measured by a stationary observer.

b) Determine the angle θ the rod makes with the x axis when it reaches its speed.

a) Determine the length of the rod as measured by a stationary observer.

b) Determine the angle θ the rod makes with the x axis when it reaches its speed.

Mechanics | Relativity

straight down onto a springboard with a force constant of

8.00 × 103 N/m. By what maximum distance does she

compress the spring?

• Using energy considerations and assuming negligible air

resistance, show that a rock thrown from a bridge 20.0 m

above water with an initial speed of 15.0 m/s strikes the

water with a speed of 24.8 m/s independent of the direction

thrown.