Answer:
288J
Step-by-step explanation:
recall the formula for kinetic energy
KE = (1/2) mv²
where m is the mass (= 4kg) and v is the velocity(=12 m/s)
hence
KE = (1/2) (4)(12)² = 288J
Answer:
10. 7n - 1 < -8
Isolate the variable, n. Do the opposite of PEMDAS. Treat the < as equal sign, what you do to one side, you do to the other. First, add 1 to both sides:
7n - 1 (+1) < - 8 (+1)
7n < - 8 + 1
7n < - 7
Isolate the variable, n. Divide 7 from both sides:
(7n)/7 < (-7)/7
n < -7/7
n < -1
n < -1 is your answer.
11. 3 > -7v + 4v
Combine like terms, then isolate the variable, v. First, add -7v and 4v together.
3 > (-7v + 4v)
3 > (4v - 7v)
3 > (-3v)
Isolate the variable, v. Divide -3 from both sides. Note that since you are dividing a negative number, you must flip the sign:
(3)/-3 > (-3v)/-3
3/-3 > v
-1 < v
v > -1 is your answer.
~
multiply 40 by 3/4
40 x 3/4 = 40*3 = 120, 120/4 = 30
he answered 30 correctly
40-30 = 10, he missed 10
Area of a circle is

. The first one, a, the radius squared is 8*8=64. So

. If you multiply in pi as 3.14, you'll have 200.96 square inches. The second one, b, the radius squared is 10*10=100. So

square kilometers. If you multiply in pi as 3.14 you'll have 314 square kilometers. The third one, c, the radius squared is 14*14=196. So

. Or you could multiply in pi as 3.14 to get 615.44 yd squared. For the last one, d, the radius squared is 22*22=484 cm. Therefore,

, or multiply in 3.14 for pi to get 1519.76 cm squared. There you go!