..... equal to the force from the engine pushing the car forward.
That's why the car is not accelerating. The horizontal forces on it
are balanced.
Answer:
a) 30 degree
Explanation:
As we know that time of flight of the projectile depends on the the vertical component of the velocity always
It is given as

now we know that

so we will have

since we know that two projectiles are projected at same speed but different angles
so smaller the angle will take smaller time
so it would be 30 degree projectile which will take smaller time
Machines are never 100% efficient because they are made by humans and we make errors and nothing we make is perfect, that's why the machines we build are not 100% accurate or efficient.
Particle-A is an electron, racing around in a cloud that's far from the nucleus.
Particle-B is either a proton or a neutron, in the nucleus.
The big clue is where you said that particle-A has very little mass
compared to particle-B. Protons and neutrons have almost identical
masses, but it's the same mass as more than 1,800 electrons !