Answer:
A. Speed is a scalar quantity and velocity is a vector quantity.
Explanation:
A scalar quantity is one that consists of only a numerical value.
Speed is a scalar quantity because only the instantaneous value is indicated, for example the speedometer of a car that tells you your speed at the moment but not where you are going or in what direction are you going.
On the other hand, velocity is a vector quantity. Because it is composed of a <u>magnitude and a direction</u>, for example 10m/s to the south is a velocity, and 10m/s is a speed.
Answer:
F = M a is a vector equation
F has the same sign as A and is in the same direction as the vector a
If a is positive then F must also be positive
Answer:
applying 1st eq of motion vf=vi+at here we have to find a=vf-vi/t , a= 1-1/5 , a=0/5 then we got a=0 here(vf value 3.6km/h is converted in standard unit 3.6×1000/3600 so we get vf=1m/s²
Answer:
a) Andrea's initial momentum, 200 kg m/s
b) Andrea's final momentum, 0
c) Impulse, = - 200 Ns
d) The force that the seat belt exerts on Andrea, - 400 N
Explanation:
Given data,
The initial velocity of the car is, u = 40 m/s
The mass of Andrea, m = 50 kg
The time period of deceleration, a = 0.5 s
The final velocity of the car, v = 0
a) Andrea's initial momentum,
p = mu
= 50 x 40
= 200 kg m/s
b) Andrea's final momentum
P = mv
= 50 x 0
= 0 kg m/s
c) Impulse
I = mv - mu
= 0 - 200
= - 200 Ns
The negative sign indicated that the momentum is decreased.
d) The force that the seat belt exerts on Andrea
F = (mv - mu)t
= (0 - 200) / 0.5
= - 400 Ns
Hence,the force that the seat belt exerts on Andrea is, - 400 N
In physics, a force is said to do work<span> if, when acting, there is a displacement of the point of application in the direction of the force. It is expressed as </span><span>Work done = force (N) X distance (m). From the problem statement, the distance traveled is zero. Therefore, the work done is zero as well.</span>