Answer:
111.5 m
Explanation:
Given that You are driving to the grocery store at 14 m/s. You are 115 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.50 s and that your car brakes with constant acceleration.
Use first equation of motion
V = U - at
Since the car is going to rest, V = 0 and a = negative
0 = 14 - a × 0.5
0.5a = 14
a = 14 /0.5
a = 28 m/s^2
Let us use second equation of motion
S = Ut - 1/2at^2
S = 14 × 0.5 - 0.5 × 28 × 0.5^2
S = 7 - 3.5
S = 3.5 m
115 - 3.5 = 111.5
Therefore, you are 111.5 metres from the intersection (in m) when you begin to apply the brakes.
Answer:
unit (v) = [ -0.199 i - 0.8955 j + 0.39801 k ]
Explanation:
Given:
v = (-23.2, -104.4, 46.4) m/s
Above expression describes spacecraft's velocity vector v.
Find:
Find unit vector in the direction of spacecraft velocity v.
Solution:
Step 1: Compute magnitude of velocity vector.
mag (v) = sqrt ( 23.2^2 + 104.4^2 + 46.4^2)
mag (v) = 116.58 m/s
Step 2: Compute unit vector unit (v)
unit (v) = vec (v) / mag (v)
unit (v) = [ -23.2 i -104.4 j + 46.4 k ] / 116.58
unit (v) = [ -0.199 i - 0.8955 j + 0.39801 k ]
Answer:
0 m/s
Explanation:
velocity= change in displacement/ time
at rest, the ball does not travel any distance
0/ t
=0
let Coefficients of Friction of Rubber on asphalt (dry) =0.7
F= Coefficients of Friction * normal force = 0.7 * 60 =42 N
so the net force of the rubber is zero, meaning it will travel at a constant speed.
When the rubber is travel at 2m/s, 42N is required to keep moving at constant speed
The answers is an electrical force.
Under normal conditions, atoms interact with each other via electrons that are furthest away from the nucleus. These electrons from the what is called the outer shell of the atom, electrons from the outer shell that can participate in chemical reactions are called valence electrons.