Answer:
t = 4.6 s
Explanation:
given,
initial velocity of the car = 23 m/s
declaration rate of car = 5 m/s²
final velocity of the car = ?
time taken to stop the car = ?
using equation of motion to solve the question
v = u + a t
v is final velocity
u is the initial velocity
0 = 23 - 5 t
we have used negative sign because there is deceleration
5 t = 23
t = 4.6 s
time taken to stop the car is equal to t = 4.6 s
The average force is -212.4 N
Explanation:
We can solve this problem by using the impulse theorem, which states that the impulse exerted on the object (the product of the force exerted and the time) is equal to the change in momentum of the object:
where
F is the net force on the object
is the time
m is the mass
is the change in velocity
In this problem, we have:
m = 26.3 kg
Solving for F, we find
where the negative sign indicates that the direction of the force is opposite to the motion of the object.
Learn more about force and momentum:
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Answer:
F = 0.00156[N]
Explanation:
We can solve this problem by using Newton's proposed universal gravitation law.
Where:
F = gravitational force between the moon and Ellen; units [Newtos] or [N]
G = universal gravitational constant = 6.67 * 10^-11 [N^2*m^2/(kg^2)]
m1= Ellen's mass [kg]
m2= Moon's mass [kg]
r = distance from the moon to the earth [meters] or [m].
Data:
G = 6.67 * 10^-11 [N^2*m^2/(kg^2)]
m1 = 47 [kg]
m2 = 7.35 * 10^22 [kg]
r = 3.84 * 10^8 [m]
This force is very small compare with the force exerted by the earth to Ellen's body. That is the reason that her body does not float away.
Answer:
t=2.10 s
u= 47.40 m/s
Explanation:
given that
h= 21.8 m
x= 101 m
g=9.8 m/s²
Lets take horizontal speed of ball = u m/s
The vertical speed of the car at initial condition is zero ( v= 0).
We know that
v= 0 m/s
now by putting the values
21.8 = 1/2 x 9.8 x t²
t=2.10 s
This is time when ball was in motion.
Now in horizontal direction
x = u .t
101 = u x 2.1
u= 47.40 m/s