Answer:
a) t = 0.90 s, b) t = 0.815 s, c) t = 0.90 s, d) x = 3.6 m, e) t = 0.639 s
Explanation:
all these exercises are about kinematics
a) The body is released from rest,
y = y₀ + v₀ t - ½ g t²
in this case when reaching the ground y = 0 and its initial velocity is vo = 0
0 = y₀ + 0 - ½ g t²
t² = 2 y₀ / g
t² = 2 4 /9.81
t² = 0.815
t = √0.815
t = 0.90 s
b) It is thrown upwards at v₀ = 4 m / s
y = y₀ + v₀ t - ½ g t²
in this case the initial and final height is the same
y = y₀ = 0
0 = v₀ t -1/2 g t²
t = 2 v₀ / g
t = 2 4 /9.81
t = 0.815 s
c) the ball is at y₀ = 4 m and its initial velocity is horizontal v₀ = 4 m / s
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 i / g
t² = 2 4 / 9.81
t² = 0.815
t = 0.90 s
d) the horizontal distance traveled is
x = v₀ₓ t
x = 4 0.90
x = 3.6 m
e) We can calculate the time to fall from I = 2 m
y = y₀ + v_{oy} t - ½ g t²
0 = y₀ + 0 - ½ g t²
t² = 2 y₀i / g
t² = 2 2 /9.81
t² = 0.4077
t = 0.639 s
Therefore, when making measurements, you should find readings around this value.
Answer:
Oxygen-18 contains 10 neutrons while oxygen-16 only contains 8 neutrons.
Explanation:
An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.
this can helps us figure out that the answer is , C, More heat is given off into its products.
most people would choose D, but i beg to differ.
Answer:
C) 469 N
Explanation:
The reading on the scale corresponds to the normal reaction exerted by the scale on the person, R.
There are two forces acting on the person:
- Its weight (acting downward), equal to , where m = 60 kg is the mass of the person and g = 9.81 m/s^2 is the acceleration due to gravity
- The normal reaction of the scale, R, acting upward
According to Newton's second law, the resultant of these two forces must be equal to the product between mass and acceleration:
where we know that since the elevator is traveling downward at 2.00 m/s^2. Solving the equation for R, we find