Answer: 7200 m
Explanation: The solution is, first convert 15 minutes to seconds.
15 mins x 60 s / 1 min = 900 s
Use the formula for speed which is v= d/t then derive for d.
d = vt
= 8 m/s ( 900s)
= 7200 m
Answer:
She is going at 30.4 m/s at the top of the 35-meter hill.
Explanation:
We can find the velocity of the skier by energy conservation:

On the top of the hill 1 (h₁), she has only potential energy since she starts from rest. Now, on the top of the hill 2 (h₂), she has potential energy and kinetic energy.
(1)
Where:
m: is the mass of the skier
h₁: is the height 1 = 82 m
h₂: is the height 2 = 35 m
g: is the acceleration due to gravity = 9.81 m/s²
v₂: is the speed of the skier at the top of h₂ =?
Now, by solving equation (1) for v₂ we have:
Therefore, she is going at 30.4 m/s at the top of the 35-meter hill.
I hope it helps you!
I beileve the answer is B
Answer:
The minimum coefficient of friction is 0.22
Explanation:
Suppose If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the curve.
We need to calculate the ideal speed to take a 85 m radius curve banked at 15°.
Given that,
Radius = 85 m
Angle = 15°
Speed = 20 km/h
We need to calculate the ideal speed
Using formula of speed


Put the value into the formula


We need to calculate the minimum coefficient of friction
Using formula for coefficient of friction

Put the value into the formula





Hence, The minimum coefficient of friction is 0.22