Answer:
D
Explanation:
A) gravity
B) force of the diver
C) air blowing out from the hockey table
D) has no know outside Force acting on it
You need to know the formula:
25 = 1/2 * g * t^2
t = √(50/g) = 2.258 s, where I use g = 9.8 m/s^2
Answer:

Explanation:
Acceleration on a VT graph is the slope of the line at the given point. We can find the slope at 3 with Δy/Δx. This gives us (4-2)/(3-(-3)) which works out to be -3m/s^2
Answer:
The puck moves a vertical height of 2.6 cm before stopping
Explanation:
As the puck is accelerated by the spring, the kinetic energy of the puck equals the elastic potential energy of the spring.
So, 1/2mv² = 1/2kx² where m = mass of puck = 39.2 g = 0.0392 g, v = velocity of puck, k = spring constant = 59 N/m and x = compression of spring = 1.3 cm = 0.013 cm.
Now, since the puck has an initial velocity, v before it slides up the inclined surface, its loss in kinetic energy equals its gain in potential energy before it stops. So
1/2mv² = mgh where h = vertical height puck moves and g = acceleration due to gravity = 9.8 m/s².
Substituting the kinetic energy of the puck for the potential energy of the spring, we have
1/2kx² = mgh
h = kx²/2mg
= 59 N/m × (0.013 m)²/(0.0392 kg × 9.8 m/s²)
= 0.009971 Nm/0.38416 N
= 0.0259 m
= 2.59 cm
≅ 2.6 cm
So the puck moves a vertical height of 2.6 cm before stopping
Answer:
Refractive index of liquid C > Refractive index of liquid B > Refractive index of liquid A
Explanation:
Let the depth of each section is h.
That means the real depth for each section is h.
Apparent depth is liquid A is 7 cm.
Apparent depth in liquid B is 6 cm.
Apparent depth in liquid C is 5 cm.
by the formula of the refractive index
n = real depth / apparent depth
where, n is the refractive index of the liquid.
For liquid A:
.... (1)
For liquid B:
..... (2)
For liquid C:
..... (3)
By comparing all the three equations
nc > nB > nA
Refractive index of liquid C > Refractive index of liquid B > Refractive index of liquid A