Answer:
1m/s [E]
Explanation:
So for displacement, its saying she went 3000m east and 2000m west. Since these two are in different directions, you would change the sign of one of them to change the direction;
3000m [E] + 2000m [W] = d
3000m [E] - 2000m [E] = d
1000m [E] = d
And its saying the time is 1000 seconds, so using velocity formula:
v = d/t
v=1000m[E] / 1000s
v = 1 m/s [E]
Assuming that there is no heat loss, and the cup is perfectly insulated, all of the energy lost by the lead will be absorbed by the water.
The heat absorbed is given by:
Energy = mass * specific heat capacity * change in temperature
The specific heat capacity of water is 4.18 joules per gram.
In order to compute the mass, we will use the fact that the density of water is one gram per milliliter. Therefore, the mass of water is 50 grams.
Now,
Q = 50 * 4.18 * (20 - 18)
Q = 418 J
418 Joules of energy were released by the lead.
Answer:
7
Explanation
There are currently seven complete periods in the periodic table, comprising the 118 known elements. Any new elements will be placed into an eighth period; see extended periodic table.
Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.81 
v₀ = initial velocity of runner in upward direction = 2.0 
v = final velocity of runner at the highest point = 0
x = distance by which center of mass of runner rise = ?
Using the kinematics
v² = v²₀ + 2 a x
inserting the values
0² = 2² + 2 (- 9.81) x
x = 0.204 m
By Newton's second law, the car slows down with an average acceleration a such that
-7100 N = (1500 kg) a ⇒ a ≈ -4.7 m/s²
If we treat the car as accelerating uniformly with this magnitude, then the car slides a distance ∆x such that
0² - (25 m/s)² = 2a ∆x ⇒ ∆x ≈ 66 m
