Answer:
Explanation:
Net electric field at the centre will be zero .
Since all the charges are equal and they all are symmetrically situated around the centre . So the electric field produced by each will cancel out each other and hence the resultant electric field will be zero . It happens because electric field is a vector quantity and therefore it adds up vectorially . All the four electric field will form two pairs , in each pair electric fields are acting in opposite direction . So they all cancel out to zero .
Answer: 14.1 m/s
Explanation:
We can solve this with the Conservation of Linear Momentum principle, which states the initial momentum 
(before the elastic collision) must be equal to the final momentum 
(after the elastic collision):
(1)
Being:
Where:
is the combined mass of Tubby and Libby with the car
is the velocity of Tubby and Libby with the car before the collision
is the combined mass of Flubby with its car
is the velocity of Flubby with the car before the collision
is the velocity of Tubby and Libby with the car after the collision
is the velocity of Flubby with the car after the collision
So, we have the following:
(2)
Finding :
(3)
(4)
Finally:
Answer:
It can cause an object to accelerate.
It can cause an object to stop moving.
It can cause an object to start moving.
It can cause an object to change directions.
Explanation:
When the velocity of an object is increased in the same direction, the object is said to have positive acceleration. If it increases its velocity in a direction that is opposite to the original direction, it is negative acceleration.
When an object that's already moving is made to stop, it is said to have decelerated. Deceleration is negative acceleration.
When an object at rest is made to move by applying a force, it is said to have accelerated to some final velocity, during its motion for some duration.
An object at rest will remain at rest is said to have no net force acting on it.
Answer:
1.) 4m
2.) 37 m
3.) 62m
4.) 2.5 s
Explanation:
1.) Given that the
Thinking distance = 1m
Breaking distance = 3m
Stopping distance = breaking distance + thinking distance
Stopping distance = 1 + 3 = 4m
2.) Given that the
Stopping distance = 52 m
Thinking distance = 15m
Breaking distance = 52 - 15 = 37m
3.) The stopping distance = 76m
Thinking distance = 14m
Breaking distance = 76 - 14 = 62m
It take the brakes 62m to slow the car down to a stop.
4.) Given that a lorry travels 28m when stopping from a speed of 4m/s. If its braking distance was 18m, what was the driver’s reaction time?
Thinking = stopping distance - braking distance
Thinking distance = 28 - 18 = 10m
Speed = distance/time
4 = 10/reaction time
Reaction time = 10/4
Reaction time = 2.5 s
5.) Question incomplete
Gravity on the surface = 4 m/s^2
Now, the acceleration due to centripetal motion, a = v^2/R
Where,
v= 10^3 m/s, R = 10^6 m
Then,
a = (10^3)^2/(10^6) = 1 m^2/s
The net gravitational acceleration = 4-1 = 3 m/s^2
The reading on the spring scale = ma = 40*3 = 120 N
