Answer:
1,3
Explanation:
As the acceleration is -10m/s^2 , that means deceleration is occurring. That means, the object is slowing down.
v=u-at
or, 0=80-10t
or, t=8 seconds
So, the object will stop in 8 seconds.
So, the correct answers are 1 and 3.
Hope, this helps you.
Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:
where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,
Now, we will calculate the number of uranium nuclei left (
):
and the rest of the uranium nuclei will become thorium nuclei (
)
dividing both:
<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>
<u>Answer:</u>
Prior to exercise, a proper warm-up of 10-15 minutes is extremely important to avoid injuries.
- Don't go too hard in the beginning and boost your activity level slowly. A good indication of a proper warm-up is that you feel sweat on your body parts.
- Don't overstretch right in the beginning as it can cause sore in your muscles and joints or stress fractures.
- Take a break if you feel sick or fatigues and use other drinks along with water to replace electrolytes and body fluids.
C is correct. Only a closed circuit can carry current, opening a switch disconnects the circuit and stops current from flowing. Remember, all current flows in loops, if you can't make a loop out of it, current can't flow, and opening a switch, assuming no other paths for current exist, will completely stop the current.
