You can use Newton's Second Law which states:
Plug in given information:
This is closest to option
b which is your answer.
Answer:
11 m/s
Explanation:
Draw a free body diagram. There are two forces acting on the car:
Weigh force mg pulling down
Normal force N pushing perpendicular to the incline
Sum the forces in the +y direction:
∑F = ma
N cos θ − mg = 0
N = mg / cos θ
Sum the forces in the radial (+x) direction:
∑F = ma
N sin θ = m v² / r
Substitute and solve for v:
(mg / cos θ) sin θ = m v² / r
g tan θ = v² / r
v = √(gr tan θ)
Plug in values:
v = √(9.8 m/s² × 48 m × tan 15°)
v = 11.2 m/s
Rounded to 2 significant figures, the maximum speed is 11 m/s.
Answer:
a = 2 m/s^2
which agrees with the third answer option provided.
Explanation:
Recall the kinematic formula for displacement under the action of a constant acceleration "a":
yf - yi = 1/2 a t^2
using the information provided this equation becomes:
9 = 1/2 a (3)^2
solve for a:
9 * 2 / 9 = a
then a = 2 m/s^2
which agrees with the third answer option provided.
