Mechanics | Relativity Answers

A bullet with speed 511 m/s and mass m = 5.00 g is shot into a stationary block of wood hanging a distance h1 = 1.00 m above the ground, as shown in Figure 1. The block is hanging by a string of length r = 0.30 m. The bullet is lodged in the block, and the block-bullet system swings so that the string makes an angle of θ = 60.0° when the string breaks, as shown in Figure 2. The block-bullet system then falls to the ground a horizontal distance d2 = 2.00 m from its position when the string breaks. Ignoring the effects of air resistance, determine the mass, M of the block of wood.

A bullet with speed 511 m/s and mass m = 5.00 g is shot into a stationary block of wood hanging a distance
h1 = 1.00 m above the ground, as shown in Figure 1. The block is hanging by a string of length r = 0.30 m. The
bullet is lodged in the block, and the block-bullet system swings so that the string makes an angle of θ = 60.0°
when the string breaks, as shown in Figure 2. The block-bullet system then falls to the ground a horizontal
distance d2 = 2.00 m from its position when the string breaks. Ignoring the effects of air resistance, determine
the mass, M of the block of wood.

A man cleaning his apartment pulls a vacuum with a force of 50N at an angle of 30°. A friction force of 40N retards the motion and the vacuum cleaner is pulled a horizontal distance of 3m. Calculate the net work done by the 50N pull

Which of the following wave functions represents the resultant wave due to the interference between the two waves:
y_result (x,t) = 4 sin⁡(2πx ‒ 20πt + φ)
y_result (x,t) = 2 sin⁡(πx ‒ 10πt + φ/2)
y_result (x,t) = 4 cos⁡(φ/2) cos⁡(πx ‒ 10πt - φ/2)
y_result (x,t) = 4 cos⁡(φ/2) sin⁡(2πx ‒ 20πt + φ/2)
y_result (x,t) = 2 sin⁡(φ/2) sin⁡(2πx ‒ 20πt + φ/2)
Other:

A 12.2 m crane weighs 18.0 kN and is lifting a 50.4 kN load. The hoisting cable (tension T1) passes over a pulley at the top of the crane and attaches to an electric winch in the cab. The pendant cable (tension T2) which supports the crane, is fixed to the top of the crane.

a) Find the tensions in the two cables.

When the crane in question above is in the position shown and lifts a 70.8 kN load, the tension T2 = 260 kN. For this situation;

b) Determine the magnitude of the force exerted by the pivot P to maintain static equilibrium.

c) At what angle to the horizontal x-axis is this force FP acting?

The wave functions of two waves traveling in the same direction are given below. The two waves have the same frequency, wavelength, and amplitude, but they differ in their phase constant.

y1 (x,t) = 2 sin⁡(2πx ‒ 20πt), and

y2 (x,t) = 2 sin(2πx ‒ 20πt + φ),

where, y is in centimetres, x is in meters, and t is in seconds.
Which of the following wave functions represents the resultant wave due to the interference between the two waves:
y_result (x,t) = 4 sin⁡(2πx ‒ 20πt + φ)
y_result (x,t) = 2 sin⁡(πx ‒ 10πt + φ/2)
y_result (x,t) = 4 cos⁡(φ/2) cos⁡(πx ‒ 10πt - φ/2)
y_result (x,t) = 4 cos⁡(φ/2) sin⁡(2πx ‒ 20πt + φ/2)
y_result (x,t) = 2 sin⁡(φ/2) sin⁡(2πx ‒ 20πt + φ/2)

you are in a card accident. your head had an initial speed of 14.4m/s when it hits an airbag which brings it to rest in 0.38s. if your head has a mass if 8.5kg, find the force on your head during the collision

A car with a mass of 1.2 x 103
kg is travelling at a speed of 12.4 m/s. What is the cars kinetic energy?
a) 92 J
b) 1.9 x 102
J
c) 7.7 x 103
J
d) 9.2 x 104
J

A cheerleader standing at the top of a human pyramid has 1801 J of gravitational potential energy. If the
cheerleader is 4.50 m above the surface of the earth, her mass must be
a) 20.4 kg
b) 31.7 kg
c) 40.8 kg
d) 95.4 kg

A 12.2 m crane weighs 18.0 kN and is lifting a 56.9 kN load. The hoisting cable (tension T1) passes
over a pulley at the top of the crane and attaches to an electric winch in the cab. The pendant cable
(tension T2) which supports the crane, is fixed to the top of the crane. Find the tensions in the two cables.

T1 = Blank 1. Calculate the answer by read surrounding text.
kN

T2 = Blank 2. Calculate the answer by read surrounding text.
kN

1