no BECQUSE POSUM BROOB SHSHSJ
Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8 
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0 
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2 
Answer:
280 N
Explanation:
acceleration = v2-v1 / time taken = (2-4 )/ 0.05 = -40 m/s^2 ( neg sign indicates slowing down )
force exerted = ma = 7 kg x -40 m/s^2 = - 280 N ( neg sign means opposite direction of initial velocity )
since the 7 kg ball is slowing down, the direction of force will be opposite of the initial velocity , and it will be 280 N
310.093k.
Given,
Best temperature for enzymes to work = 98.6°F
Unknown :
We need to convert the temperature from fahrenheit to kelvin.
Writing down the equation to be used in the problem's solution correctly:
K = (F x 0.55) + 255.37
F = (K - 255.37) x 1.8
The temperatures are expressed in kelvin (K) and fahrenheit (F), respectively.
There first equation would be significantly more quicker to use :
K = (98.6 x 0.555) + 255.37
= 54.723 + 255.37
= 310.093K
➤ The activity and rate of an enzyme reaction typically increase with temperature, while a decrease in temperature slows the enzymatic reaction. Each enzyme's activity peaks at its individual optimum temperature, and it decreases above and below that point.
Find more on enzymes at : brainly.com/question/1596855
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a. There is nothing suggesting that the balloon is accelerating horizontally, so we can assume that its horizontal speed is constant. The time before the balloon crash into the hill is simply the distance between the balloon and the hill divided by its velocity. Remember that velocity is simply the amount of distance that a object travels in a certain amount of time:

b. Know that you know the maximum amount of time that the balloon can take to gain 28m of altitude, the minimum acceleration can be found using the equations constant acceleration motion:

where a is the acceleration, v_o is the initial vertical velocity, 0 as the balloon is not moving vertically before starting to ascend. xo is the initial position, which we will give a value of 0m.

c. As we said before, there isn't any kind of force that accelerates the balloon horizontally, therefore, we can consider that its horizontal velocity is constant and equal to 2.8m/s
d. Acceleration is the amount of change in velocity after a given amount of time. So, with the acceleration and the time we can fin the velocity:
