Well we can't see the picture that the teacher has, and we have to figure out what's in the picture from some clues in the answer choices. The picture seems to show an atom with 3 protons and 3 neutrons in the nucleus, and 3 electrons whizzing around the nucleus.
If that's what's in the picture, then Mike is correct (first choice), because the atomic number shows the number of protons in all atoms. There are 3 protons and the atomic number of lithium is 3.
Second choice . . . False, because electrons are not involved in the atomic mass.
Third and fourth choices . . . both false; sadly, Joan is woefully unclear on the concepts.
Many plutons clump together as they grow through the crust.
Speed of car = 130 km/hr = 130*5/18 = 36.11 m/s
Let the time taken for catching up be t,
Distance traveled by car = 36.11 t
Acceleration of police vehicle = 10.1 km/h/s = 10.1*5/18 = 2.81 m/
Distance traveled by police vehicle in time t =
Here u = 0, a = 2.81 m/
So, Distance = 0*t+
Comparing both the distances we have
So after 25.70 seconds police vehicle will catch car.
Answer:
Kicking a ball involves you applying a force because you are pushing it with your foot and that makes it fly up. Once you shoot something into the air, the gravity force pulls it back down to the Earth, which is a different type of force.
Explanation:
hope this helps :)
Answer:
.
Explanation:
The box is sliding with a constant speed in a fixed direction (to the right.) In other words the velocity of this box is constant. Hence, this box would be in a translational equilibrium. The acceleration of this box would be zero.
By Newton's Second Law of motion, the net force on this box would be . In other words, forces on this box are balanced.
The question is asking for the size of the friction on the box. Assuming that the floor is horizontal. The friction on this box would also be horizontal,
The only other force that could balance that friction would be the push to the right. The direction of this push is horizontal (to the right.) Hence, the entirety of that would be in the horizontal direction.
Thus, forces on this box in the horizontal direction would be:
- The push to the right.
- Friction that opposes the rightward motion of the box (that is, to the left.)
Since these two forces must balance each other, the size of the friction would also be .