A light year is a distance.
It's the distance that light travels in a year, through vacuum.
The distance is about 5.875 trillion miles.
The nearest star outside our solar system is about 4.2 light years from us.
Sorry to have rambled on for so long.
Answer:
Speed is a scalar quantity it has only magnitude. So in the given scenario the student actually described about the velocity.
Explanation:
In this situation, student is describing that the speed is -10 m/s. The speed with the negative sign is wrong because speed is a scalar quantity and scalar quantities have only magnitude, they do not have direction. So, his statement is wrong because he is describing the speed with the negative sign.
And also we know that velocity is a vector quantity, so it has magnitude as well as direction also. So in this situation, the student is actually want to describe the velocity because he is mentioning the magnitude in a particular direction.
Answer:
Because the gravitational attraction of the Sun hold them in motion around it
Explanation:
For an object travelling in a straight path at constant velocity, the net force acting on the object must be zero.
The planets in the Solar System, however, do not experience a zero net force: in fact, the Sun exerts a gravitational attraction on them, whose magnitude is given by

where
G is the gravitational constant
M is the mass of the Sun
m is the mass of the planet
r is the average distance between the Sun and the planet
Due to the presence of this force, the Sun makes the planets 'deviating' from their straight path, forcing them to following an elliptical path around the Sun.
Answer:
The three "accelerators" are: the throttle, the steering wheel and the brakes.
Explanation:
Acceleration means change in velocity. But this change may be in module or in direction.
Car throttle will increase the velocity module of the car and brakes wil diminish it. On the other hand, the steering wheel will change the direction of the velocity.
Hope my answer helps you. Have a nive day!
Answer:
8 time increase in K.E.
Explanation:
Consider Mass of truck = m kg and speed = v m/s then
K.E. = 1/2 ×mv²
If mass and speed both are doubled i.e let m₀ = 2m and v₀ = 2v then
(K.E.)₀ = 1/2 ×2m(2v)²
(K.E.)₀ = 8 (1/2 × mv²) = 8 × K.E.