When a wave hits an object,energy from the wave is both absorbed and reflected off the object

A spring-loaded gun can fire a projectile to a height h if it is fired straight up. if the same gun is pointed at an angle of 45

Naily [24]

When firing straight up:
v^2 = u^2 - 2gh, where v = final velocity = 0, u = initial velocity, g = gravitational acceleration, h = maximum height attained.

Then,
0 = u^2 - 2gh
u = Sqrt (2gh) ---- (1)

When firing at 45°,
Initial velocity, U = u Sin 45 = Sqrt (2gh)·Sin 45

Maximum height, H = U^2*(Sin Ф)^2/2g

substituting;
H = [Sqrt (2gh)·Sin 45]^2*(Sin 45)^2]/2g
H = [2gh*(Sin 45)^2*(Sin 45)^2]/2g
H = [h*(Sin 45)^4] = h/4

Therefore, maximum height when the gun fires at 45° is a quarter of maximum height when the gun fires vertically up.

6 0

3 years ago

If a golf ball is swinging on a pendulum on the planet mars (g=3.711 m/s²) and it takes 7 seconds to complete one oscillation, w

sertanlavr [38]

T = 2*pi*Sqrt (L/g)

T = Period = Time to complete one oscillation, L = Length of the pendulum, g = gravitational acceleration.

Then,

L = {T/(2*pi)}^2*g = {7/(2*pi)}^2*3.711 = 4.606 m

4 0

3 years ago

Which are dangerous places to put a flammable substance? Check all that apply.

Murrr4er [49]

Answer:

near a flame and a hot plate

Explanation:

7 0

3 years ago

2. A large pack of snow of mass m sits at the top of a trail at a ski resort. Friction keeps the snow pack in place, but when it

Aleks [24]

Answer:

tanΘ

Explanation:

Let gravitational acceleration be g. When the avalanche starts to occur, the gravity force that is parallel to the slope is the same as friction force.

Gravity force that is parallel to the slope can be written as:

G = mgsinΘ

The friction force is the product of normal force and coefficient:

$F_f = N\mu$